Affiliates automatic activation, how to do it?

Hello,
I don't understand how to automatically activate new users as affiliates.

New users:
the only way is to have them register through Hikashop and click the checkbox for the affiliation? Will this automatically activate them as partners?

Existing users:
Is there a quick way for an existing user to request affiliation and be activated? I tested with a demo account but in their affiliate page the activation is set to "NO" and there is no option to request activation.

Thank you

Thank you Nicolas,

another question:
users that are registered through Joomla but not through Hikashop need to register again through the Hikashop form in order for them to be activated as affiliates?

Performing a registration in Joomla will create an HikaShop user too, but since it's not the HikaShop registration form, the affiliate data (such as the rest of the HikaShop fields) won't be provided by the user. So it need to fill them later and they are pages for that.

I understand but I could still have user register via Joomla and then use a mass action to activate them as affiliate (since a Hikashop user is being created too), isn't it?
They could fill in the email for payment and their customer details (address etc.) later, that i snot really a priority for me.

Thank you